A variety of positive lock pins are well known in the art. Positive lock pins are typically utilized to quickly install a secure connector in a joint or other location to thereby lock two or more objects together.
One known positive lock pin that is widely utilized is generally referred to as a pip-pin. As is known, pip-pins are typically used to lock two or more objects together in applications where a clamping force is not needed. The locking function of these pip-pins is accomplished through the utilization of a protruding ball lock mechanism. As is known, the ball lock mechanism is comprised of a pair of balls that are positioned to communicate with holes in opposing sides of the pip-pins. Each of the pair of balls extends outwardly through a respective hole such that its outermost portion extends beyond the diameter of the pip-pin. In this locked position, the balls prevent the pip-pin from being removed from the hole into which it inserted. To remove the pip-pins, the ball lock mechanism is retracted which allows the pip-pin to be removed from the hole into which it is inserted.
One known application for these pip-pins includes the attachment of Ground Support Equipment together with associated flight hardware. Another known application for these pip-pins is for the International Space Station where they are used to assemble mechanisms and truss structures in space. These pip-pins have applications that are both temporary and permanent. In either event, current pip-pins have a reliability problem where the balls, which form part of the locking mechanism, can fall outwardly through the hole and therefore become detached from the pin. Obviously, if the balls fail, the retention capability of the pip-pins is diminished. Further, the loose balls can contaminate critical hardware and may cause malfunction.
One of the principal reasons that the ball mechanisms fail is due to vibration forces that act on the pip-pins. With current pip-pins, the ball devices are swaged into place to provide a retention mechanism for the pin. Because the ball devices are swaged into the holes from the outside, the large vibrations and forces that act on the pip-pins, due to the applications in which the pip-pins are employed, can cause the ball devices to fall out of the holes. As is known, the swaging process provides relatively weak retention capabilities. Accordingly, efforts have been made to increase the retention capabilities of these balls, including by increasing the amount of swaging of the ball devices. This increased swaging, however, decreases the amount of retention capability of the pin. This is because, by increasing the amount of swaging, the ball devices protrude out of the pin a lesser distance. This increased swaging further requires the diameter of the hole in which the pip-pin is placed to be machined to tighter tolerances in order to insure retention of the pip-pin in the hole.
Because of the unreliability of these pip-pins, they must be frequently replaced and/or repaired when failed. This increases the cost of the pip-pins as well as the associated service costs. Moreover, if the pip-pins fail altogether, this failure can have a more significant impact on the application in which they are being utilized.